Hypertension (HTN) is a major health problem in the United States placing some 58 million Americans at increased risk for stroke, myocardial infarction, kidney failure, and peripheral vascular disease. African Americans are especially vulnerable to HTN, with as many as 38% of the adult Black population affected with the disorder. Although pharmacologic management of HTN is often effective, medications are not without complications and untoward side effects. Consequently, there has been a great deal of interest in the development and application of behavioral treatments for the management of HTN. The present study is a single randomized clinical trial of exercise with three long-term objectives. The first is to evaluate the efficacy of aerobic exercise in reducing blood pressure in older African American men and women with mild HTN (Systolic blood pressure (BP) 140-180 mmHg and Diastolic BP 90-105 mmHg); the second is to examine the mechanisms by which blood pressure is reduced; and the third is to investigate the effects of exercise on cognitive performance and related aspects of quality of life.